Abstract: A one pin crystal oscillator for satellite tuner, with all load capacitance integrated on chip has been realized.Due to the structure of the oscillation and the use of MOS gate capacitance for the load capacitance, the chip area can be very small.Based on 0.18um CMOS technology, the chip area is 0.023mm2.This oscillator can work in 2 modes: crystal outside mode and source outside mode.When the oscillator work in crystal outside mode, it generates rail to rail sine wave, and the start time of oscillation less than 1ms.And it allowed 0.1V³.3V sine source in when it works in source outside mode.